As you cannot use a cellular Apple Watch in Turkey, you might as well get the GPS only model and save money.
The GPS only model can do EVERYTHING the cellular model can do, as long as the iPhone is nearby. The cellular model can leave the iPhone at home and still provide some services. The GPS model can still track you exercise and play stored music and podcasts. It just cannot connect to the internet without the iPhone or being on a WiFi network
Please read the following
https://support.apple.com/en-us/HT205547
and pay attention to the footnotes.